Glow lamp mounting



May 13, 1952 PETERSON 2,596,166

GLOW LAMP MOUNTING Filed Dec. 15, 1949 3 Sheets-Sheet l F l G. l 42 4s F l G 4 INVENTOR THOMAS F. PETERSON,

ATTORNEYS May 13, 1 T. F. PETERSON 2,596,166

GLOW LAMP MOUNTING Filed Dec. 15, 1949 5 Sheets-Sheet 2 INVENTOR THOMAS F. PETERSON,

ATTORNEY-5L May 13, 1952 PETERSON 2,596,166

GLOW LAMP MOUNTING Filed Dec. 15, 1949 3 Sheets-Sheet 3 FIG. 5

THQMAS F. PETERSQN 5 ATTORNEYS Patented May 13, 1952 UNITED STATES PATENT OFFICE GLOW LAMP MOUNTING Thomas F. Peterson, Shaker Heights, Ohio Application December 15, 1949, Serial No. 133,034

17 Claims. 1

This invention relates to glow lamps that require a leak resistor (200,000 ohms) inseries therewith but consume infinitesimal amounts of current. Such lamps find utility, particularly for the illumination of switch cover plates, door knobs and the like, so that the latter can be located in the dark; and another application of such lamps coming within the purview of the present invention is that of changeable electric signs. The invention is herinafter set forth in such embodiments.

As commonly constructed, the leak-resistor for a glow lamp is made as a separate element and connected in series with a socket that receives the glow lamp. The present invention, among other objects, provides in one of its embodiments a simplification thereover that greatly reduces both the cost and labor of installation by combining in a conductive lamp support the requisite resistance as a unitary structural element. This is accomplished by a lamp base-gripping support, as of rubber or the like made semi-conductive by the incorporation of conductive particles, preferably conductive carbon black, such as acetylene black (i. e., its resistivity is reduced from millions of megohms to fall within a range of a few ohms to hundreds of megohms per cubic centimeter; see Printed Circuit Techniques, Bureau of Standards circular 468 on Resistor Paints, pages 7, 8). In association therewith, the leads to the support are likewise made semi-conductive to supply at least part of the leak resistance and avoid the hazards of short circuits involving the flow of large currents.

Several embodiments of the invention are illustrated in the accompanying drawing in which: Y

Fig. 1 is a partial vertical cross-section of a wall switch and cover plate showing the mounting of a neon lamp in the plate;

Fig. 2 is a rear elevation of a modified embodiment illustrating a supplementary plate for positioning under a cover plate;

Fig. 3 is a vertical cross-section on the line 33 of Fig. 2;

Fig. 4 is a partial vertical cross-section of a changeable electric sign and a modified lamp for use therewith;

Fig. 5 is a cross-section of a portion of a sign assembly illustrating continuous semi-conducting films and lamp mountings for cooperation therewith;

Fig. 6 is a fragmentary cross-section of a further modification of a sign structure;

Fig. 7 is an elevation showing conductor contacts to the semi-conducting layers and current flow lines; and

Fig. 8 is a modification of Fig. '7

The embodiments of Fig. 1 is an application to a common type of wall switch (the switch mechanism being omitted), in which a ceramic block II is supported within a box I2 with leads l3 and 14 connected to terminals I5 and [6 on the front of the block that can be. one vertically above the other as shown or diagonally disposed; the cover plate I! of customary molded insulating material is attached to the box by screws 18 and I9. One departure provided by the present invention lies in an opening 2| in the cover plate, preferably, though not necessarily, on a line with one of the switch block terminals. In the opening is a grommet or sleeve 22 of resilient semi-conductive material, with an aperture 23 therethrough for a neon lamp 24 and of a size to hug the base 25 of the lamp closely and so hold it in position; having the opening in alignment with a switch terminal permits the lamp to be inserted far enough through the aperture for the central lamp terminal 26 to directly contact a switch terminal as l5. From the grommet 22, there extends a semi-conductive lead or path 21 on the back of the cover plate; a semi-conductive rubber or equivalent paint, brushed on the plate, has been found adequate as a lead, and it is painted in a direction to bring it opposite another switch terminal as IS. A spring contact 28 is shown attached to the switch terminal IE to press against the conductive path; but the contact 28 can take other forms, such as a spring or resilient semi-conducting rubber boss extending from the cover plate to contact the terminal.

The foregoing provides an extremely simple and readily applied, yet adequate, construction for illuminating the switch when the switch is open, and the light bulb or other device is in the circuit to complete path to ground; thus it offers both the conductance and the resistance required for the neon lamp operation, and this without any danger of shorts. As shown, the circuit is from the-switch terminal l5 to the lamp terminal 26 through the lamp to the conducting base 25 and the grommet 22, and thence by the path 21 and spring contact 28 to the other switch terminal I6. In its operation it has been discovered that the life of the neon lamp is very greatly extended if the grommet and/or leak path is between the live side of the line and the neon lamp bulb.

A modification of the foregoing is the provision of a separate or supplementary sheet or plate for placement under the cover plate without necessitating any change in the latter; this is illustrated in Figs. 2 and 3 of the drawing. The plate 30 can be a sheet of insulating material, such as paper impregnated with a resin to give it body and stifiness and hold it in shape. It is provided with an opening 3| and a curled-over shield or reflector to extend over and beyond the cover plate and provide for mounting a socket 33 for a neon light 34 and so throw light on the face of the cover plate. The back of the sheet has bosses 35 projecting sufficiently to be pressed into contact with switch block terminals; as these terminals on the switch block occur in pairs in any two of the positions-A and D, A and C, B and C, B and D--four bosses, which, as explained in connection with the contact 28 of Fig. 1, can be of resilient rubber inserted or attached to the plate 30, are accordingly supplied. The bosses the provided with semi-conducting material on their terminal contacting surfaces 35, and extending from these surfaces are semi-conducting paths as by painting or printing, one path 3? connecting the bosses 35A and 35B and the other path 38 connecting the bosses 35C" and 35D. These paths lead respectively to the socket 33 and to a lamp-base central contact 39. The operation of the supplementary sheet is like the pre ceding embodiment of Fig. 1.

Another application of the invention is illustrated by Fig. 4, namely, a changeable sign. Mounted in a frame 4| is an insulating support 42 of penetrable material, such as cardboard, cork, etc. On the back of the support is painted or adhesively secured a semi-conductive coating or layer 43, and on the front of the support is a mesh or screen preferably of resilient rubber or other elastomer threads 45 that are semi-conducting. The mesh is of such size that a neon lamp base can be pushed between the threads to grip the base and yet have adequate electrical contact therewith. The coating 43 and the screen 44 in combination have the resistance requisite for a lamp operation and thus function as the equivalent of the grommet 22 and conductive path 21 of Fig. 1. For establishing the lamp circuit, a pin 4'6 extends from the central terminal of the lamp to penetrate the support 42 and contact the coating 43; other means can be substituted for the penetrating pin terminal to secure contact with the coating or layer 43, but the pin makes a satisfactory contact and requires no modification of the support 42. A backing 43 protects the coating 43.

The operation of the foregoing sign structure is evident. A neon lamp (or any number of them) is pushed where desired through the mesh 44, and the pin 46 penetrates the support to contact the coating 43.

The sign embodiment is capable of various modifications. One such is illustrated in Fig. 5, wherein a sheet insulating base 50 has continuous semi-conducting film or layer coatings 52 on the faces. For establishing a circuit across the coatings, a penetrating pin 53 can be used, the end 54 that pierces the coating '52 being bare while the side 55 of the pin passing through the coating 5| has insulation 56 about it to isolate it from the coating 5|. As shown, the pin 53 can be duplicated, as at 51, and a spring clip lamp support 58 connected to the two pins; the button or central contact 59 on the lamp base 6!] then contacts the layer 5| for closing the circuit. Or the single pin can be provided with a head 52 to contact the button, the head being insulated on the under side 63 and gripped by a conducting sleeve socket 64 for the lamp; conducting contacts 65 extending from the socket give added bearing to support or maintain the lamp in position.

The insulation 50 can be cork or other selfsupporting material. Or it can be a flexible insulation sheet of suitable thickness with the semiconducting layers 5|, 52 on each side, in which case the sheet can be mounted on any supporting base, such as a wall, cork board, etc., or it can be hung from a support. A further modification shown in Fig. 6 is the use of a magnet plate 66 as the supporting base to attract and hold the penetrating pin 53 and thus aid in securing the lamp in position.

Figs. '7 and 8 illustrate ways of conveying current to the semi-conducting layers in the foregoing sign embodiments. Preferably, these take the form of conductors ll, 12, extending along opposite edges and on opposite sides so that each conductor is in contact with opposite extremities of each of the semi-conducting layers. In Fig. 10, these are shown as angular conductors i3, 14, at diagonally opposite corners and extending partially along the adjacent edges. Binding posts l5, 16, or other equivalents such as leads, can be attached to the ends of the conductor for connection into a circuit. With such connections, there is no danger of shorting when the layers are made semi-conducting; this is demonstrated by the lines of force 11 to a lamp pinned on the sign base which are indicated by full lines on the exposed side and by dotted lines on the reverse side. No matter then where the lamp may be inserted, the total or added resistance across both the layers from one conductor and through the lamp to the other remains approximately the same for any location of the lamp.

The invention has other useful applications. In its essence it comprises means for contacting the base terminals of a glow lamp, which means functions both as a conductor and also, preferably in conjunction with a semi-conducting lead thereto, as the resistance required for the lamp operation. Materials of a semi-conducting nature are, for example, described in Patents 2,322,702, June 22, 1945, and 2,446,387, August 3, 1948; as therein explained, they are non-metallic organic insulating bases brought into the semiconducting range by the incorporation of conducting carbon black, e. g., acetylene black, and it is such materials that are herein intended by the term semi-conducting.

What is claimed is:

l. Glow lamp mounting comprising in combination a support including a resilient and expandible rubber-like semi-conducting grommet for engaging a lamp and a terminal thereof, and conductors for contacting the grommet and the other lamp terminal, the combination of grommet and conductors affording in itself the resistance requisite for a lamp operation by at least one of said elements of the combination being of smut-conducting material.

2. Glow lamp mounting comprising in combination an insulating support and a pair of conductors carried by the support, an expandible conducting lamp-engaging means for association with the support and for establishing contact between one of the conductors and a lamp terminal, the second conductor providing contact for the other lamp terminal, the combination of lamp engaging means and conductors affording in itself the resistance requisite for a lamp operation by at least one of said elements of the combination being of semi-conducting material.

3. Glow lamp mounting comprising in combination an insulating support penetrable from one face to the other by an extension from one of the two terminals of a lamp, and conductive means on opposite faces of the support for contact by the two lamp terminals, said conductive means in combination affording the resistance requisite for the lamp operation by at least one of them being of semi-conducting material.

4. Glow lamp mounting comprising in combination a sheet of insulating material, semiconducting surfacings on both faces of the sheet, a conductor associated with an extremity of one of the surfacings and a second conductor associated with the other surfacing at an opposite extremity, whereby a glow lamp with terminals in contact with the two surfacings is afforded the requisite resistance additively by the two surfacmgs.

5. Glow lamp mounting comprising in co1nbination a sheet of insulating material and conducting surfacings on both faces of the sheet for contact by lamp terminals, at least one of the surfacings being semi-conducting to supply resistance requisite for a lamp operation.

6. Glow lamp mounting comprising in combination a cover plate for a switch block, a semiconducting grommet carried by the plate and having an aperture therethrough for receiving a lamp, and a semi-conducting path painted on the back of the cover plate in electrical continuity with the grommet and for contact with a terminal on the switch block, the lamp providing the return contact to the block.

7. Glow lamp mounting comprising in combination an insulatin plate for placement behind a cover plate of a switch assembly, bosses projecting from the plate for contact with terminals on the switch block of the assembly, a pair of semi-conducting paths on a surface of the plate and extending from the bosses, a lamp base engaging support of semi-conducting material carried by the plate in electrical continuity with one of said paths, and a terminal on the other of said paths for contact with the central lamp terminal.

8. Glow lamp mounting comprising in combination an insulating sheet support, a mesh surfacing of semi-conducting threads on one face of the support for engaging a lamp base and a semi conducting surfacing on the other face of the support, whereby a lamp provided with a terminal for penetrating the support establishes a circuit between the two surfacings and the surfacings provide the resistance requisite for the lamp operation.

9. Glow lamp mounting comprising in combination an insulating sheet support, semi-conducting surfacings on the faces of the support, and a lamp base-engaging means comprising a pair of pins for penetrating the support and basegripping means connecting the pins, said pins having insulation about them to isolate them from the surfacing penetrated by them in order to contact the other surfacing.

10. Glow lamp mounting comprising in combination an insulating sheet support, semi-conducting surfacings on the faces of the support, a lamp socket for receiving the base of a lamp, and a pin carried by the socket but insulated therefrom to contact the remote surfacing on the support, said pin being insulated from contact with the proximate surfacing.

11. Glow lamp mounting comprising in combination an insulating sheet support, semi-com ducting surfacings on the faces of the support, and a magnet plate in contact with one of the surfacings whereby a penetrating pin terminal of a lamp is attracted to hold the lamp in place.

12. Structure for cooperation with an electrical device dependent upon resistance in circuit therewith for its operation comprising in combination a resilient and expandible rubber-like member for engagement with the device and a terminal thereof, and a conductive lead extending from the member, said combination of member and lead in itself providing resistance requisite to the operation of the device by at least one of the elements thereof being of semi-conductive material.

13. Structure for cooperation with an electrical device dependent upon resistance in circuit therewith for its operation comprising in combination a resilient and expandible rubber-like semi-conductive member for engagement with the device and a terminal thereof, and a semiconductive lead extending from the member, said combination providing in itself resistance requisite to the operation of the device.

14. Structure for cooperation with an electrical device dependent upon resistance in circuit therewith for its operation comprising in combination an insulating plate, a boss projecting from the plate for contacting a circuit terminal, and a semi-conductive lead extending from the boss and along the plate to contact a terminal of the device, said boss having its circuit terminal-contacting surface in electrical continuity with the lead to provide resistance requisite to the operation of the device.

15. Structure for cooperation with an electrical device dependent upon resistance in circuit therewith for its operation comprising in combination a support for the device, a boss projecting from the support for contacting a circuit terminal, and a semi-conductive lead along the support and extending from the boss for series connection with a terminal of the device, said boss having its circuit terminal-contacting surface in electrical continuity with the lead to provide resistance requisite to the operation of the device.

16. Structure for cooperation with an electrical device dependent upon resistance in circuit therewith for its operation comprising in combination flexible insulation, a boss projecting from the insulation for contacting a circuit terminal, and a semi-conductive lead extending from the boss and along the insulation to contact a terminal of the device, said boss having its circuit terminal-contacting surface in electrical continuity with the lead to provide resistance requisite to the operation of the device.

17. Structure for cooperation with an electrical device dependent upon resistance in circuit therewith for its operation comprising in combination flexible insulation, a boss of resilient rubberlike semi-conducting material projecting from the insulation for contacting a circuit terminal, and a semi-conductive lead extending from the boss and along the insulation to contact a terminal of the device, said boss having its circuit terminalcontacting surface in electrical continuity with the lead to provide resistance requisite to the operation of the device.

THOMAS P. PETERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 697,856 Lefebre Apr. 15, 1902 1,067,024 Hall et a1 July 8, 1913 2,265,419 Brand et al Dec. 9, 1941 2,327,396 Boardman Aug. 24, 1943 2,428,167 Linton Sept. 30, 1947 2,447,541 Sabee et al Aug. 24, 1948 2,448,606 Linton Sept. 7, 1948 

